Answer:
$770 favorable
Explanation:
The spending variance for a flexible budget will be calculate as follow:
actual activity x standard rate  - actual cost
1,300 x 3.90 = 5,070 standard cost
actual cost    4,300
Variance: Â Â Â Â Â 770 favorable
This variance is favorable, as the actual cost were lower than expected, the company saved cash in the supplies espending.